Tool handle fastening



Patented Mar. 9, 1,948

UNITED STATES PATENT OFFICE TOOL HANDLE FASTENING George R. Hess, Washington, D. C.

Application April 18, 1947, Serial No. 742,414

7 Claims. (Cl. 306-33) This invention relates generally to fastenings for tool handles, and more specifically to such a fastening as comprises a handle the upper end portion of which is adapted to be spread laterally at its approximate median point in order to ll concave recesses formed on the inner surfaces of the tool head, the said spread being accomplished through the medium of suitable wedging means disposed in a central kerf of the handle, thereby resulting in a handle securement which is positive and more efficient in use than those heretofore proposed.

With these and other objects in view the in- Vention resides in the novel details of construction and combinations of parts as will be disclosed more fully hereinafter and particularly covered by the claims.

Referring to the accompanying drawings forming a part of this specification and in which like numerals designate like parts in all the views- Fig. 1 is a vertical sectional view through a securement made in accordance with this invention;

Fig. 2 is a vertical sectional view of a modified form of securement, the parts in this view being shown in their relative association just prior to the operation of the wedging means for spreading the handle into its secured position with reference to the tool head;

Fig. 3 is a top plan view of the complete securement according to the modification illustrated in Fig. 1; and

Fig. 4 is a composite view in side elevation of the upper end portion of a, handle, and a wedging means associated With the kerf formed in said handle.

A metallic tool head, generally indicated by the numeral 2, is provided with the usual opening 3, two of whose facing wall surfaces such as indicated at 4 are substantially concave, which surfaces may be the result of casting or may be deflnitely roughened for the purpose of additionally gripping the upper end portion 5 of the wood handle generally identified by the numeral 6, said upper end portion being-of reduced dimension to t the opening 3 tightly at the extremities 'l and 8 thereof as well as to provide the shoulder 9 for limiting the extent of the handle into the tool head. ASaid end portion 5 is provided with a kerf l0, extending axially downward substantially to said shoulder, for receiving therein a strong (preferably metallic) wedging means by which the relatively weaker material of the handle on each side of said kerf is displaced laterally, or spread, or bowed in order to ll -the recesses formed by the concave facing Wall surfaces 4 o the aperture 3 of the tool head.

l The end portion 5 of the handle is formed with substantially parallel flat outer surfaces as indicated at Il, and said kerf is formed with substantially convex facing wall surfaces as indicated at I2 to provide a kerf formation which is substantially of hour-glass shape, all as yclearly illustrated in Fig. 4, the narrowest dimension of said kerf being approximately at its mid-depth. Thus it will be understood that any strong wedging means operating upon the convex surfaces of said kerfv will impart a force to the relative Weak material of the handle suflicient to create' the aforementioned lateral spread of the upper portion of the handle to contact the concave surfaces of the tool head aperture.

The wedging means according to Fig. 1 comprises a metallic member l5 having substantially parallel sides which are tapered inwardly at the bottom edge as clearly shown at i6 in Fig. 4, the degree of taper being sufllcient to insure ready entry of said lower edge into the kerf l0 of the tool handle. The surfaces of said sides may be provided with outwardly extending burrs or similar projections Il which are suitably -inclined to cause the wedge to grip the material of the handle and thus prevent the wedge from working out of the kerf. Such a wedge, when driven into the kerf of the handle, Will cause the lateral displacement of the material of said handle, as shown in Fig. 1, to ll the concave recesses of the tool head aperture, whereby the handle is securely locked at the median point of its tool head engaging portion by a parallel wedge which exerts its lateral pressures substantially equally from top to bottom of vsaid wedge, thereby differing materially from the heretofore well-known wedges of triangular cross-sectional shape which have the great tendency to slip, loosen and work out. This type of wedge may be of single extent as indicated in full lines in Fig. 3, or for large.

handles it may :be of plural extent (cruciform or T shape for example) as indicated additionally by the dotted lines at l 8.

In some instances it may be found desirable to change tool heads with respect to a single handle and therefore a modification of this invention is illustrated in'Fg. 2 as comprising a removable' Wedging means, of screw-actuated type, which maybe tted into the hour-glass shaped kerf previously described. This removable wedge comprises a shaft 20 oppositely threaded at its ends for engagement withl one -or more conic or tapered members such as 2.I` and 22 which are caused to move vertically in the kerf by rotation of the shaft through the application of a screw-driver or similar tool applied to the slot 23 in the exposed end of said shaft.

Thus it will be understood that at the time the handle is inserted in the tool head 2, the wedge members 2| and 22 will be in the positions illustrated in Fig. 2 at the outer ends of the shaft, with the straight sides I of the handle in spaced relation to the concave surfaces `4 vof the tool head aperture. When the shaft is rotated,*the wedge members 2| and 22 will be caused to move toward each other and approach the median point of the portion 5 of the tool handle, and in this travel said wedges will operate against the convex surfaces I2 of the kerf to spread the material -of the handle laterally and so force the straight .sides I-I .into engagement with the concave surfaces 4 of the tool head aperture, and so lock the handle to the tool head.

A reverse rotation `of :the shaft Will cause the wedge members to move reversely or .away from each `other thereby releasing the pressure on the .tool handle .at the median point of the portion 5 thereof. While the resiliency of the handle material may have :become slightly impaired `through use of the tool, -yet the .handle may be driven-out of the tool head. Obviously, the shaft may lberotated in manners `other than that herein illus-- trated .and above described; for example, theend 4of -the shaft maybe headed instead of recessed fior the accommodation of the rotating tool. Also, the wedges 2| and 2v2 may be lsubstantially conic or may be elongated members extending `the `full width :of Ithe kerf but having .sloping sides for engagement with the surfaces of said kerf. It would probably be undesirable to have true cones for the wedges unless the outer surfaces `thereof were suitably ribbed or grooved to prevent their turning with the shaft.

The tools contemplated in association with this invention are many and Varied, such for example as hammers, hatchets, axes, picks, mattocks, sledges, etc., the only .requirement being that the metallic tool head have a handle-receiving aperture having substantially concave facing wall surfaces whereby the median dimension of the aperture is greater than the dimensi-on `of the aperture at an outer face of .the tool head, in order that the `material of the handle may be laterally displaced :to cause such material to spread or bow outwardly to .fill the concave recesses formed by the sides of said aperture. With respect to the wooden handle, the only requirement is that the outer surfaces of the aperture-engaging end portion be substantially parallel and flat, and that the `opposing surfaces ofthe kerf therein be substantially convex that when the wedging means operates upon said convex surfaces, there will result the lateral displacement as aforesaid.

It is obvious that those skilled in the art may vary the details of construction and arrangements of parts without :departing from the spirit of this invention wherefore it is desired not to be limited to the exact foregoing disclosure except as may berequired by the claims.

What is claimed is:

.1. A tool handle fastening comprising a tool head provided with a handle-receivingV aperture havin-g substantially concave facing wall surfaces, a handle having an end portion engageable with said aperture, said end portion formed with substantially hat outer surfaces and further formed with a kerf having substantially convex facing wall surfaces, and wedging means engageable with said kerf to displace the material of said handle laterally whereby to cause a flattening of the convex surfaces of said kerf and thereby to bow the flat outer surfaces of the handle into the concave wall portions of the tool head aperture.

2. A tool handle fastening comprising a tool head provided with a handle-receiving aperture having substantially concave facing wall surfaces, a handle having an end portion engageable with 'saidaperture said end portion formed with substantially flat -outer surfaces and yfurther formed with a kerf having substantially convex facing wall surfaces, the convexity of the wall surfaces -cf said .Icerf being approximately equal to the concavi'ty of the wall surfaces of said aperture, and :Wedging .means engageable with said kerf to dis- .place the material of said handle laterally whereby 'to Acause a iiattening of the convex surfaces of said rkerf and thereby to bow the flat outer surfaces of the handle into-the concave Wall portions .of the tool head aperture.

'3. A tool handle fastening comprising a tool head provided with a handle-'receiving aperture having substantially concave facing Wall surfaces, va handle having .an end portion engageable with said aperture, said end Aportion formed with substantially flat outer surfaces and 'further 'formed with a kerf having substantially vconvex facing wall surfaces, and wedging means comprising a .member having substantially .flat parallel sides engageable with said lkerf to displace the material of said handle laterally whereby to cause a fiattenng of the convex surfaces of said kerf and thereby to bow the flat outer surfaces of the handle into the concave wall portions of the tool head aperture.

4. A tool handle fastening comprising a tool head provided with a handle-receiving aperture having substantially concave facing wall surfaces, a handle having an end portion engageable with said aperture, said end portion formed with substantially flat outer surfaces and further formed with a Vkerf having substantially convex facing wall surfaces, and wedging means comprising a pair of oppositely movable conic members engageable with said kerf to displace the material of said handle laterally whereby to cause a flattening .of the convex surfaces of ,said kerf and thereby to bow the flat outer surfaces of the handle into the concave wall portions of the tool head aperture.

5. A tool handle fastening comprising a .tool head provided with a handle-.receiving aperture having substantially concave facing wall surfaces, a handle having an end portion engageable with said aperture, said end portion formed with substantially .fia-t outer .surfaces and further formed with .a kerf having substantially convex facing wall surfaces, and screw-actuated wedging means engageable with said kerf to displace the material of said -hand-le laterally whereby to cause a flattening of the convex vsurfaces of said kerf .and thereby to `bow the :dat youter .surfaces of the handle into the concave wall portions of the tool head aperture.

6. A tool .handle fastening comprising .a tool head having .a handle-receiving aperture therein, a median dimension-of the aperture being greater .than the dimension of the aperture at a face of the tool head, a 4handle having an end portion adapted to slip into the -aperture of the tool head, said end having a vkerf formed therein of substantially hour-glass .shape in axial cross-section, and wedging means engaging said kerf to displace the material of said handle laterally to fill the space created by the greater median dimension of the handle-receiving aperture.

'7. A tool handle fastening comprising a tool head having a handle-receiving aperture therein,

a median dimension of the aperture being greater 5 than the dimension of the aperturev at a face of the tool head, a handle having an end portion adapted to slip into the aperture of the tool 6 head, said end having a ker formed therein, said kerf having its median portion of reduced d1- mension to form a restriction and wedging means engaging the restricted portion of said kerf to displace the material of said handle laterally to ll the space created by the greater median dimension of the handle-receiving aperture.

GEORGE R. HESS. 

